相关论文: A green's function approach for surface state phot…
We present a model for the photoelectrons emitted from the surface of a Topological insulator induced by a polarized laser source. The model is based on the tunneling of the surface electrons into the vacuum in the presence of a photon…
Motivated by recent photoemission experiments on the surface of topological insulators we compute the spectrum of driven topological surface excitations in the presence of an external light source. We completely characterize the spectral…
We show that the degree of spin polarization of photoelectrons from the surface states of topological insulators is 100% if fully-polarized light is used as in typical photoemission measurements, and hence can be significantly "higher" than…
Topological insulators are characterized by Dirac cone surface states with electron spins aligned in the surface plane and perpendicular to their momenta. Recent theoretical and experimental work implied that this specific spin texture…
The surface bound electronic states of three-dimensional topological insulators, as well as the edge states in two-dimensional topological insulators, are investigated in the presence of a circularly polarized light. The strong coupling…
Topological insulators are a new phase of matter that exhibits exotic surface electronic properties. Determining the spin texture of this class of material is of paramount importance for both fundamental understanding of its topological…
We construct a Green function, which can identify the topological nature of interacting systems. It is equivalent to the single-particle Green function of effective non-interacting particles, the Bloch Hamiltonian of which is given by the…
A differential coupling of topological surface states to left- versus right-circularly polarized light is the basis of many opto-spintronics applications of topological insulators. Here we report direct evidence of circular dichroism from…
Recently discovered materials called three-dimensional topological insulators constitute examples of symmetry protected topological states in the absence of applied magnetic fields and cryogenic temperatures. A hallmark characteristic of…
Using the Green functions method we study transport properties of surface electrons in topological insulators in the presence of a correlated random exchange field. Such an exchange field may be due to random magnetization with correlated…
Three-dimensional topological insulators represent a new quantum phase of matter with spin-polarized surface states that are protected from backscattering. The static electronic properties of these surface states have been comprehensively…
We study the photocurrent response of topological insulator surface states to circularly polarized light for arbitrary oblique incidence. We describe the surface states within a Dirac model, including several perturbations such as hexagonal…
Gapless surface states on topological insulators are protected from elastic scattering on non-magnetic impurities which makes them promising candidates for low-power electronic applications. However, for wide-spread applications, these…
This work presents a Green's function approach, originally implemented in graphene with well-defined edges, to the surface of a strong 3D Topological Insulator (TI) with a sequence of proximitized superconducting (S) and ferromagnetic (F)…
The dyadic Green's function of the inhomogeneous vector Helmholtz equation describes the field pattern of a single frequency point source. It appears in the mathematical description of many areas of electromagnetism and optics including…
A general technique to analyze the classical interaction between ideal topological insulators, and electromagnetic sources and fields, has been previously elaborated. Nevertheless it is not immediately applicable in the laboratory as it…
We characterize the topological insulator Bi$_2$Se$_3$ using time- and angle- resolved photoemission spectroscopy. By employing two-photon photoemission, a complete picture of the unoccupied electronic structure from the Fermi level up to…
We demonstrate that the terahertz/infrared radiation induced photogalvanic effect, which is sensitive to the surface symmetry and scattering details, can be applied to study the high frequency conductivity of the surface states in…
We study the spin polarization of the electrons on the surface of topological insulators under a dc electric field or a circularly polarized light by using Keldysh Green's function formalism. When a dc electric field $E_x \sim 10^{3} {\rm…
Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses back-scattering and protects the coherence of these states in the presence of non-magnetic scatterers. In contrast, magnetic…